EP-A 376279 corresponding to JP-A H3(1991)-157308, for instance, describes guanidine derivatives having pesticidal activity and a process for producing the derivatives. Moreover, as an improved production process for the guanidine derivatives, EP-A 452782 corresponding to JP-A H5(1993)-9173 discloses a production process via an isothiourea derivative having a cyclic diacyl group as shown in the following schema 1. ##STR2## wherein R.sub.1, R.sub.2, R.sub.4a, and R.sub.5a are the same or different, H or a hydrocarbon group which may optionally be substituted; A' is a divalent hydrocarbon group which may optionally be substituted; Q' is a heterocyclic group which may optionally be substituted; X' is an electron withdrawing group; Y.sub.1 and Y.sub.2 are the same or different, a leaving group; n is 0 or 1.
Furthermore, EP-A 375907 corresponding to JP-A H2(1990)-288860 discloses guanidine derivatives having pesticidal activity, and the following process for producing the derivatives. ##STR3## wherein R.sup.1' and R.sup.2' are hydrogen or C.sub.1-4 alkyl, R.sup.4' is C.sub.1-4 alkyl, Z is a five- or six-membered heterocyclic group having at least one nitrogen atom which may be substituted by halegen or C.sub.1-4 alkyl, R.sup.5' and R.sup.6' are hydrogen or C.sub.1-4 alkyl.
However, in these processes for producing the guanidine derivatives, there are some problems such that a mercaptan compound of RSH (wherein R is a hydrocarbon group which may optionally be substituted) having bad smell is formed as a by-product.
In the above state of the art, the object of present invention is to provide a process which is advantageous to an industrial mass production of guanidine derivatives in a higher yield by simple and convenient reaction procedures without bad smell, novel intermediates therefor, and a process for producing the intermediates.